Admins can now add users directly from the admin portal via a modal
form (name, email, password). Created users are pre-approved and can
log in immediately.
- POST /api/admin/users endpoint (AddUserHandler, AddUserCommand)
- Add user modal in AdminPage with inline error handling
- 5 new integration tests covering auth, happy path, duplicate email,
and immediate login; fix SQLite file-lock on test cleanup via
SqliteConnection.ClearAllPools()
- 4 new E2E tests covering modal open/close, happy path, and duplicate
email error